Chusetts



II. F. KENWOIIIIIY.

POROUS SUBSTITUTE FOR LEATHER AND T. HE LIKE. APPLICATION FILED SEPT. 26, I9Is.

1,3 10,703. I Patented July 2 2, 1919.

j UNITED Jsra'rns- PATENT yoEErcE.

HERBERT E. HEnwoRTHm-or ScITUATE, MASSACHUSETTS, AssIeNoR To HENWORTHY BROTHERS COMPANY, or SToUGHToN, MASSACHUSETTS, A coRroRATroN or Messa- CHUSETTS.

ASpeciication of Letters Patent.

Patented July 22, 1919.

Application led September 26, 1916. Serial No. 122,308.

To all whom it may con/Jem: 4 i

Be it known that I, HERBERT F. KEN- WORTHY, a citizen of the United States, residing at Scituate, in the county of Plymouth and State of Massachusetts, have linvented new and useful Improvements in Porous Substitutes for Leather :and the like, of which the following is a specificaftion.

This .invention relates to` processes and products forporous leather substitutes. It is an object of the invention to provide a material which will have utilitysimilar to that of'leather, with additional advantages. In particular, theobjects of the invention are to produce a material which may be workable like leather, with customary tools,-

methods and machinery for working leather; be flexible, and retain this throughout its life at all ordinary atmospheric temperatures; be durable; be a nonconductor of heat; be resilient; have nonslip characteristics, and in general 'be cheaper than leather, as well as more useful than leather in various other respects. It

is another object that this material shall be free from some of the disagreeable features that are associated lwith rubber.

Ito

Notwithstanding numerous elforts` here-` tofore made, no one, so far as I am aware, has hitherto mastered the /problem of com# pounding materials for the abovev purposes. Important features of-the process which I have found successful are to provide a tough, thick, porous substance, of a filmy nature, in which are bers, preferably of animal origin, such as wool, which supplef ment the strength and elasticity of the hlm, and to a degree determine and maintain its interior structural aspect. This said substance, which has many characteristics of the lm produced by what lare known as drying oils, incases and clings tightly to the bers, binding them flexibly together.

At the' same time the bers are entangled with and cling to each other; and the smaller spaces between them are more orless filled,

either with-said lm` or with small solid mineral particles embedded therein. Film eax-inlay pores or spaces which permit a considerable degree of flexibility of the mass as a who1e,a exibility whichresults from the presence of these spacesfcoupled with they elastic nature of the bers and of the lm, and of the attachments of the bers to each otherand to the `lm. If the said pores are unfilled, air can pass in and out and through the product thus described, nevertheless the lopenings are so small and theoily characteristic of the material surrounding the orices is such, that water does not readily enter.l This may be because dthe surface is not wetted .by the water and the skin tension of water globules is not broken. However, as the product thus described is in fact porous, water can be made to penetrate it'; and water will do so under suitable conditions of repeated exure or of pressure, so that this' product maybe commercially described as being only partly waterproof, or merely moisture proof.

For the porous, brous, hny structure it is preferred to use blown oil, japan, and turpentine coupled with wool felt and comminuted mineral solids such as oXid of zinc or carbonate of lead. The structure may be made by mechanically combining the bers Iwith the other materials, liquids being rst thinned with a volatile diluent` such as naphtha, herein called fugitive oil and by raismg their temperature so that as a thin liquid they penetrate among the bers, carrying 'alsothe pulverized solids in among them. The subsequent evaporation of thenaphtha leaves a porous structure in which air is accessible' to the remaining liquids all through the mass, so that they dry into the elastic lmy condition. Color canbeadded either in the lling or in the `initial liquid; and the product'canbe finished mechanically by sand papering, by embossing or by other-suitable methods. The structure .of the nished product is shown more orV less diagrammatically in the accompanying drawing, in which,

Figure l'is a cross section through a preferred and ordinary form of the product;

Fig. 2'shows a similar sectionthrough 'a modication having a Ycentral web and Fig is a similar section through a modication having both the central web and an,

embossed coating, the thickness of the coatinbeing exaggerated.

- or explanation, of the process and product more in detail, the following illustrative exampleis given: Take 250 pounds of fluffy oxid of zinc, made by the so-called French or German process; 85 pounds of carbonate of lead; gallons of blown oil.; 10 gallons of japan; and I0 gallons of turpentine; and mix them thoroughly so that the solids are suspended and uniformly distributed throughthe liquid. Pigment may be introduced to give desired color. When ready to use, naphtha is added, varying in amount according to -weather conditions. The amounts may be in the vicinity of about 50 per cent. by volume, making the liquid of a specific gravity of about 1.100. The precise proportions of ingredients above described may be varied. And in fact it has been found well in some cases to add about 10 per cent. of blown voil and about 30 per cent. drier, and thewhole being well stirred in a tank.

Thesheets of fibrous faibricwhich mayr be` wool felt are then lput in, and left immersed u-ntil the liquid and its suspended soli-ds have I entered thoroughly into them. The completeness lwith which the liquid passes into the spaces between the fibers is noticeable, for a large, quantity of the felt can 4be immersed without-raising the level of the liquid mixture in the tank more than a trifie. If the felt be of an inch thick, several hours of such immersion has been found sufficient, the liquid being well stirred. If the felt be moved through the liquid (in strip form, moving around rollers, with bends and angles therein, a few minutes suflices. If the felt be thicker, a longer. time is requisite. The combined liquid, solid and fibrous material then is dried, preferably in la room having a temperature in the vicinity of 160 Fahrenhelt, through which room air is blown,A

passing over Aand around the sheet material with its liquid contents. During this the' naphtha is withdrawn by evaporation, and so 1s recovered; and the liquid material dries by a process of oxidation into tough, filmy form, incasing and gripping in its film the fibers and the solid particles, and leaving pores. Thereafter the material is cooled, `with ythe drying process still continuing slowly to a more perfect stage, which is con- .veniently done by simply turning off the heat and allowing the blowing of air to oontinue at atmospheric temperature. The sheet material then passes through apparatus for giving its surface any desired finish, as for example, sand papering and embossin machines.

he material thus finished has many vof the characteristics of leather as regards utilities, and has many that are superior or additional to those of leather. When used in connection with the manufacture of shoes,

an innersole it has the following characteristics, none of which are true of leather: it can be worked dry, without mulling in water; it neither 'shrinks nor swells, as leather does under changes of moisture from the wearers foot; it is fast in color, whereas leather stains white hosiery; it is of uniform flexibility, whereas the fiexibility of leather varies in different. hides and in different parts of 'the same hide; it will not check or crack as leather does; it is cheaper thany leather; and there are further econo mies resulting incidentally such as the saving of time and labor of mulling, involving a saving of expense; the elimination of the sorting operation, and the freedom of the stock from culls. Among still other advantages are, that it is orous permitting passage ofair, that whlle not absolutely waterproof, it is moisture proof; and that it is a non-conductor `of heat; and that it retains its resiliency well. It can be made exceedingly flexible by the use of hot water.

An important feature in the attainment of the desired qualities is` the omission of rosin from Iamong the ingredients, this being a material that has often been proposed vfor use for leather substitutes, and also the omission of other stiff ingredients .such as a shellac and glue, which either will stiffen permanently, or will not penetrate properly i before they set, or which unless protected by other chemicals are liable to soften un-` der exposure to Water. Without saying that' these ingredients must be lalbsolutely excluded, experience has shown that a better product is produced without them.

The particular material which is employed for the fibrous fabric may depend in part'on the use to which the product is to be put, strong and coarse woolen lfibers being selected for uses such as shoe soles,F 1,10

and particularly for cases where the product is to be further impregnatedy for use for out-soles as is disclosed and claimed in my co-pending application for patent Serial No. 122,307.y 4For other uses, such as for power transmission belts, the felt sheet may contain a central web-of fabric as indicated in Fig. 2 to which the material on each side 'is attached by felting. Such a web eliminates stretching and contributes to the strength, while the felt and web are found v of in practice to be so thoroughly joined to- 1,310,7oa t does not slip, thus always giving full sciency; that it does not stretch; and that it is not hurtby water falling upon it. To adapt the 'material for upholstery or for trunks and bags, the felt with web center may be used, and the product may be finished with an enamel coating and lby embossing as indicated in Fig. 3', as so called artificial leather is now finished;

and the product thusl finished has the advantage over leather substitutes which are made on woven fabric bases that it does not fray when cut. The product may also be used for many other purposes for which leather and other fabrics are now used. It will be understood that the invention is not limited to the precise steps and materials above indica-ted. Naphtha, for example, is a type of what isreferred to -in the claims as fugitive oil, meaning a liquid 'which is introduced and remains only temporarily, being readily evaporative' at ordinary temperatures or' at the temperature to which the mixture is subsequently subjected. The naphtha may be aided in its function of reducing the viscosity of the liquid by adding 'heat to the mixture, although if this in- 'creases the wastage'of naphtha it may be preferred to omit the heating at this stage, unless this step is carried out in a closed space. kIn lthe drying which immediately follows, it is preferable to arrange the sheets in parallelism in a closed space, andvthen to force a blast of heated air through the passages between the sheets, as'by power fans. By suitably confining the air, which thus becomes laden with naphtha, the naphtha mayfbe recovered for repeated use. A temperature of 100 more or less abovey the atmosphere increases the speed of evaporation' and also increases the speed and com- -pleteness with which the process of oxidation of the drying oils goes forward.` When the `drying oil composition is made of the particular ingredients and proportions mentioned,'its elasticity after the oxidation process is noticeable, resembling that of rubber.

This coupled with the inherent elasticity of the fibers makes thecompleted productl both fiexible and elastic.

The specific material, which is preferred for use as the principal basis for the filmy characteristic of the completed product, is blown oil, which has in practice been found advantageous; but it appears that'other fatty bodies capable-of'diyin into a hard and,tough state might be suistituted. In vthe claims, the phrase intensely-drying is inbefore described. Linseed oil as com-- monly used in paintsxisnot suitable for,this.

, Still less is it desirable `that the liquid be so 'pervasive as to penetratfe the cellular commonly used are alreadysaturated more This prevents.

or less withV their own oil. such penetration by other oil, so that the oil used as herein described merely fills the spaces between fibers binding them together and filling the mass.

What is claimed is 1. The art of making resistant sheet material comprising the immersing of a thick fibrous fabric having a ,felted surface in a mixture including intensely drying oil', which at atmospheric temperature is a relatively thick liquid, fugitive oil, and a pow der, thereby impregnating the said fabric throughout its body and substantially filling its pores; and afterward exposing the whole to air, Whilel the .interfibrous spaces are substantially filled with said mixture, whereby the said filling becomes a binder stiffiy supportin the fibrous fabric.

2. T e art of making resistant sheet maf terial comprising the immersing of a thick fibrous fabric havinga felted surface in a mixture including blown oil, japan, turpentine, fugitive oil, and a powder, thereby impregnating the said fabric throughout its body and substantially filling its pores; and afterward exposing the whole to air, While the interfibrous spaces are substantially filled with said mixture, whereby the said filling becomes a binder stilily supporting the fibrous fabric.

3. The art of making resistant sheet material comprising the immersing of a thick fibrous fabric having a felted surface in a mixture including blown oil, jap-an, turpentine, a readily evaporative mineral 'solvent, fiuffy oxid of zinc and carbonate of lead, thereby impregnating the said fabric throughout its body and substantially filling l its pores; and afterward exposing. the Whole to air, while the interfibrous spaces are substantially filled with said mixture, whereby the said filling becomes a binder stifiiy supporting the fibrous fabric. y

4. The art of making resistant sheet material comprising theimmersingof a thick mixture, which at atmospheric temperatue is a relatively thick liquid# including about .five parts, byweight, 'of an intenselysdrying oil/mixture, and four'parts, by weight, of apowder, thinned byaddition of fugitive oil, thereby impregnating 'the said fabric its pores; and afterward exposing the Whole to air, while the interfibrous spaces are substantially filled with said mixture, whereby the said lfillin becomes a binder stifiiy supporting the fi rous fabric.

5. The art of making resistantsheet ma- 4terial comprising the immersing of a thick i151/ fibrous fabric having a felted surface in aw '-thr`oughout its body and substantially filling used as 1a Aconvenient term for'l signifying rous, thickfabric, having pulverized solids fibrous fabric having a felted surface in a mixture including about three parts, by

weight, of blown oil,l oneI part of japan, one part of tur entine, three parts of fluffy oxid of zinc an one ,part of corbonate of lead, the said oxid and carbonatev being in the form of powder and the whole mixture being thinned by addition of fugitive oil and by rise of temperature above the atmospheric; thereby impregnating the said fabric throughout its body and substantiallylfilling itspores; and afterward exposing the y whole to air, while the inte fibrous spaces are substantially filled with said mixture, whereby the said filling becomes a binder v stifily supporting the fibrous fabric.

powder, thereby impregnating the said- 4fabric throughout its body and substantially 6. The art of making resistant sheet material comprising the immersing of a thick fibrous fabric having a felted surface in a mixture including intensely-drying oil,

fwhich at atmospheric temperature is a relatively thick liquid, fugitive oil, and a 'thick fabric, having pulverized solids 1n its midst, its filmy parts extending throughout its body,- surrounding and binding together its fibrous and pulverized parts, and consistving substantially of oxidized drying oils.

9. A felted, fibrous, filmy, slightly porous,

'thick fabric, having pulverized solids in its midst, its filmy parts extending throughout its body, surrounding and binding together 'its-fibrous and pulverized parts, and being composed of oxidized drying oils'including blown oil.

10. A felted, fibrous, filmy, slightly poin its midst, its filmy parts extending throughout its body, surrounding and binding together its fibrous and pulverized parts, and being composed of oxidized `drying oils,

the said filmy and fibrous portions being elastic.

11. A Vslightly porous, thick fabric having a fibrous web with a body of fibrous material on each side of it, attached to it by felting, having pulverized solids in its midst,l the whole being held together by a filmy product composed of oxidized drying oils extending throughout its body, surrounding and binding together its fibrous and pulverized parts.

12. The art of making a resistant mass which `consists in thoroughly impregnating a fibrous thick body having a felted portion with a liquid of a character to dry to a thick hard `and tough state, and disseminating powder throughout the whole, with its particles among the fibers and embedded in said liquid, and then permitting said liquid to dry while the interfibrous spaces are substantially filled with said liquid, thereby binding fiexibly together the incased fibers 'with greatly reduced porosity of the fabric.

13. The art of making a resistant mass which consists in thoroughly impregnating a thick body, of fibrous absorbent material having a felted portion with a mixture which is thick at atmospheric temperature and includes blown oil and a removable diluent therefor and a powder, thus causing said oil, diluent and powder to penetrate and lodge within theinterstices and pores of said fibrous body whereby the liquid incases the fibers, and then causing the re` moval of said diluent and the setting of said blown oil While so positioned to a hard and tough state, binding individual fibers.

` f 14. As a new article of manufacture, a

felted, fibrous, filmy, slightly porous, thick composite sheet in the form ofa shoe sole, and adapted for use as an inner sole of a shoesaid sheet being composed of an elastic fibrous body, a powder disseminated through it, and an elastic, filmy material extending throughout its body, surrounding and binding together its fibrous and pulverulent parts and composed substantially of oxidized drying oils, including blown oil. Signed by me at Boston, Mass., this twenty-fifth day of September, 1916.

HERBERT F. KENWORTHY.

vWitnesses: v- Evnlm'rr E. KENT, n CHARLEsA. Comxcnr'. 

